THE FEASIBILITY OF RICE HUSK APPLICATION AS ENVELOPE MATERIAL IN SUBSURFACE DRAINAGE SYSTEMS

Many studies have been conducted on the role and importance of subsurface drainage in groundwater table control to discover new techniques and more economical solutions, particularly relating to different pipes, envelope materials and their installation. This research was conducted to investigate the applicability of rice husk in drainage as a drain envelope material. It was compared with standard sand and gravel envelopes. Some of the physical and hydraulic properties of rice husk such as bulk density, void ratio, gradation curve and hydraulic conductivity were measured. A physical model that simulated a part of the drain trench enabling groundwater table control was used to simulate land drainage in the laboratory and to test filtration and water conductivity of a rice husk envelope. The experiments were carried out in two soils that required envelope material based on standard methods. The results of this study showed that hydraulic conductivity of the rice husk even under large loads, was high enough to guarantee its hydraulic function as an envelope. Furthermore, the rice husk envelopes had appropriate filter function compared to mineral envelopes. Copyright (C) 2012 John Wiley & Sons, Ltd.